Valve for brakes



' H. w. PRICE VALVE FOR BRAKES Jan. 18, 1938.

Filed Oct. 9, 1935 2 Sheets-Sheet l INVENTOR. HAROLD M PRICE BY WK)- ,yA TTORNEYI Jan. 18, 1938. H. w. PRICE VALVE FOR BRAKES Filed Oct. 9,1935 2 Sheets-Sheet 2 ww 2 0 6 4 2 w M 6 n J 4 l w a -u a 6 .n x

f 2 4 O 0 4 9 M s 3 Z ma c5 8 m. M a a 1 H6 a b O a 6 w r 24 w mwm Datented Jan. 18, 193

Bendix sw m. cts

Corporation, Ind, acorporation of Indiana South Bend,

Application October 9, rats, Serial No. 44,165

ZCiaims. (Cl. 121-465) This invention relates'to valves and isillustrated by a valve arrangement especially adapted for use in avacuum power braking system for automobiles.

5 One of the objects of the invention is to provide a resistance to theoperation of the valve, proportional to the power being controlledthereby.

One of the features of the device illustrated is 10 the arrangement ofthe parts of the valve to provide a chamber in which the air is of. thesame non-atmospheric pressure (a partial vacuum such as may be createdby a source of suction as illustrated) as in the power cylindercontrolled 15 thereby and to provide that the non-atmospheric airpressure in this chamber acts upon a movable member connected to thevalve'actuator.

Further objects and features-of the invention will be apparent after areading of the subjoined 2o specification and claims and after aconsideration of the accompanying drawings, in which:

Figure 1 is a diagrammatic view of a brake hookup employing a valveconstructed according to my invention;

25 Figure 2 is a view in'section of a valve such as that used in thehookup shown in Figure 1; and

Figure 3 is a view in perspective of the movable valve element of Figure2.

The brake operating hookup shown in Figure 1 30 is shown and describedand is claimed in a copending joint application of Harold W. Price andEarl Price. Serial No. 41,442. It includes a power cylinder III havingan operating piston connected by a tension link I! and an overrunningjoint I4 36 with a. brake operating cross shaft l6. The cross shaft i6is arranged to operate wheel brakes such as It and 26 by means oftension connections such as 22, 24, 26 and 28. The cylinder I is securedto the frame of the automobile and is to controlled by a valve 30, towhich it is connected by means of a conduit 32. The valve 30 iscontrolled by a pedal 34 to which an operating element 36 of the valveis pivotally connected by a floating lever 33 and a pedal link 60, thelink 40 45 being plvotally connected both to the lever 36 and the pedal34. The lever 38 is also pivotally connected to a tension rod 4| havingan overrunnin connection 42 with the cross shaft l6. Thus the reactionon the operating element 36 i0 is transmitted to the pedal :4 and byvirtue. of the relative distances between the three pivotal connectionsof the lever 36-, the reaction or feel is multiplied and the lostmovement of the pedal is decreased. By virtue of the fact that the leverI 33 is floating and that it moves with movement of the cross shaft inapplying the brakes, the operator must followup the brake applying move:

maintain the brake applying force.

In the event of failure of the vacuum power the. brakw may be applied bythe foot pedal 34 through the link 40, the lever 36, the link 4! and theconnection 42. Furthermore, the brakes may be applied by a hand lever 44through a link 46 and an overrunning connection 48. This hand leverarrangement will normally be used only in applying the brakes whenparking.-

The arrangement of the valve to provide a reaction on the operatingelement 36 proportional to the brake applying force exerted by thecylinder II) is one of the important parts of my invention. For thispurpose I provide the valve 30 comprising a central member 52 formedwith a longitudinal main bore'54, a radial tapped oper- 2o atingconnection bore 56, a tapped vacuum ccnnection bore 58, and adiametrical air connection bore 60. The bore 56 is connected to thecylinder ill by the conduit 32, and the bore 58 is connected to theintake manifold 33 by the conduit 33. The forward end of the bore 54 is'tapped to receive a plug 62 formed with a ring 64 for pivotally mountingthe valve on the chassis of the automobile.

Adjacent to said forward end the member 52 30 is reduced in diameter andover the reduced portion there are telescoped three sheet metalcontainers 66, 68 and ill which cooperate with strainer material 12 toform an air strainer. The members 66 and 68 are formed with openingssuch as 14 to allow the passage of air therethrough. The member 66 isheld in place by the pressure of the strainer material I2 and themembers 68 and iii are clamped in place by a nut 16 threaded on the plug62.

I place in the bore 54 a substantially cylindrical valve member 18 whichis formed however with a. longitudinally extending passage 80 and withan annular recess 82. It may be seen that with the valve'member 1a inthe position shown, the bore 56 is connected by the passage 86 with thebore 60 and thus through the openings 14 and the strainer material I2with the atmosphere.

' However, if the valve member 18 is moved a short distance to the left,a portion 84 thereof covers the bore 66 and shuts off the communicationwith the atmosphere. Should the valve member 16 be moved further, thebore 58 will be connected to the bore 56 by way of the annular recess82. Thus in the position shown, the cylinder I0 is conne'cted only tothe atmosphere but if the valve member I8 should be moved slightly tothe left the cylinder I would be out off both from the atmosphere andthe manifold and if it should be moved still farther to the left thecylinder would be connected with the manifold only.

The forward end of the bore 54 has a spring 86 which is provided forpurposes later to be described and which bears at one end on the plug 62and at the other on the valve member I8 being held in position by anextension 88 on the valve member. A small bore 90 connects the end ofthe bore with the air strainer and thus vents the end of the bore.

The rearward end of the member 52 is flared as at 92. Secured to theflared portion by bolts such as 93 is a vented cover 94 through whichthe operating element 36 extends. Clamped between the flared portion 92of the member 52 and the cover 04 is a diaphragm 96. The central portionof the diaphragm is clamped to the operating element 36 by a nut 98threaded on the inher end of the operating element 36. Protecting platesI00 and I02 are positioned on each side of the diaphragm, and outside ofthe plates there are positioned washers I04 and I06. These are allclamped to the element 36 by a nut I08 also screwed on said element 36.Thus movement of the element 36 requires a corresponding movement of thediaphragm 96 and resistance to movement of the diaphragm is transmittedto th element 38.

The passage 80 extends as is shown by the dotted line to the rearwardend of the element l8 and therefore the pressure on the inner side ofthe diaphragm corresponds to that in the bore 58 and the cylinder I0.Inasmuch as the pressure on the outside of the diaphragm is atmospheric,the differential in pressure is the same as the differential acting onthe piston in the cylinder l0 and the reaction on the element 38 isproportionate to the braking force exerted by the cylinder I0 althoughmuch less because the area of the diaphragm 96 is much smaller than thearea of the piston.

The rearward end of the member I8 contacts with the nut 98 and therearward movement of the member isthus limited by the movement of thenut. The spring 86 bearing on the forward end of the member I8 causes itto follow the movement of the nut 98. A spring III) stronger and H6secured to the operating member 30,-.

cushions the return. of the operating element.

, lap the valve.

The passage 80 cooperates with a screw II8 to guide the member I8 andprevent rotation thereof in the bore 54.

In the operation of the above described braking system, pressure exertedon the pedal 34 acts through the link 40 and the lever 38 to pull on thelink 4I and the operating element 36. Due

- to the resistance of the brake return springs, the

link 4I holds and theelement 36 is moved compressing the spring II 0 andallowing the spring 86 to move the member I8 to a position in which thebore 58 is connected through the recess 82 with the bore 56. Thus air iswithdrawn from the forward end of the cylinder I0 and force is exertedby the piston thereof to pull the link I2 and operate the brakes. Thisreleases the link M to reverse the movement of the lever 38 and In orderto apply the brakes further, the operator must follow up the movement ofthe brakes by a corresponding movement of the pedal 34. The forceexerted by the cylinder I0 in applying the brakes corresponds to thereaction felt on the pedal by reason of the differential in pressures onopposite sides of the diaphragm 96 as previously explained.

It is to be understood that the above described embodiments of myinvention are for the purpose of illustration only and various changesmay be made therein without departing from the spirit and scope of theinvention.

I claim:

1. For use with a power operating system, a valve for controlling thepassage of fluid under differential pressure to a power operator,comprising a casing formed with an inlet port, an outlet, and an exhaustport, a valve member movable in said casing, a pressure responsive meansmovable with said valve member, and an operating element connected tosaid pressure responsive means, the valve member being formed with alongitudinally extending passage connecting a space adjacent thepressure responsive means with said outlet, and the casing beingprovided with an anti-rotation means extending into said passage.

2. For use with a power operating system, a valve for controlling thepassage of fluid under pressure differing from atmospheric pressure to apower operator, comprising a casing formed with a pressure chamber, aninlet for said fluid, an

atmospheric inlet, and an outlet, a valve member movable in said casing,a pressure responsivemeans movable with said valve member and acted onby the pressure in said chamber, and an operating element connected tosaid pressure responsive means, the valve member being formed with alongitudinally extending passage connecting a space adjacent thepressure responsive means with said outlet, and the casing beingprovided with means for preventing rotation of said valve membercomprising an element extending into said passage.

. HAROLD W. PRICE.

